Metal cans, glass bottles and a variety of plastic containers have been used in the field of packing containers. Among them, plastic containers have been used for various applications from the standpoint of their light weight, shock resistance and cost. Here, however, though the metal cans and glass bobbles do not permit oxygen to pass through their walls, the plastic containers permit oxygen to pass through their walls to a degree that cannot be neglected causing a problem in regard to storing the contents.
To solve such a problem, there has been proposed a multilayered container having a wall of a multilayered structure, at least one of the layers thereof being a layer of a resin having excellent oxygen-barrier property, such as of an ethylene-vinyl alcohol copolymer. However, though the ethylene-vinyl alcohol copolymer exhibits excellent oxygen-barrier property, the oxygen-barrier property wanes if it is used under highly humid conditions. Therefore, it has been demanded to develop containers capable of exhibiting high oxygen-barrier property even when they are placed under highly humid conditions.
In order to remove oxygen remaining in the container or to remove oxygen infiltrating from the exterior, further, there have also been proposed multilayered containers provided with a layer of an oxygen-absorbing resin composition that contains ethylenically unsaturated hydrocarbons and a transition metal catalyst (patent documents 1 and 2). At the time of absorbing oxygen, however, the oxygen-absorbing resin composition generates bad-smelling components which are the oxidized and decomposed products of low molecular weights, and the taste and flavor of the content are spoiled by the bad-smelling components.
In order to solve such problems, the present applicant has proposed a plastic multilayered structure including an oxygen-barrier layer, an oxygen-absorbing layer and a thermoplastic resin layer containing zeolite of the high-silica type and having a high silica/alumina ratio (patent document 3).